Radiation exposure is detrimental to human health. For example, a comprehensive review of available biologic and biophysical data supports a “no-threshold” risk model for radiation exposure since the risk of cancer may increase linearly at low doses of radiation without a threshold. Radiation has the potential to cause a small increased risk of malignancy in humans. (National Research Council. Health Risks from Exposure to Low Levels of Ionizing Radiation: BEIR VII Phase 2. Washington, D.C.: National Academies, 2006.) The head and neck (in particular the brain, eyes, and thyroid) are particularly sensitive to radiation. Accordingly, radiation exposure to the head and neck may be particularly detrimental to the health of the patient.
However, many different medical radiologic procedures or examinations, such as electrophysiological procedures, cardiac catheterization, angioplasty, cardiac stenting, cardiac valve procedures, and orthopedic procedures, require the use of radiation. Although many different technologies attempt to avoid or minimize radiation during these procedures, there is still a moderate to high x-ray exposure as evidenced by reported fluoroscopy in numerous studies. (Cano O, Alonso P, Osca J, et al. Initial experience with a new image integration module designed for reducing radiation exposure during electrophysiological ablation procedures. J Cardiovasc Electrophysial, 2015; 26: 662-670., Valderrabano M, Greenberg S, Razavi H, et al. 3D cardiovascular navigation system: accuracy and reduction in radiation exposure in left ventricular lead implant. J Cardiovasc Electrophysiol, 2014; 25: 87-93.) Implant procedures may incur a higher exposure to the practitioner since the x-ray generator may be closer to the practitioner.
As shown in FIG. 17, during a radiologic procedure, a radiation source 120, such as an x-ray tube below a table 110 holding the patient 10, may emit radiation 122 (e.g., x-rays) as an active or direct radiation beam 121 that is aimed toward an examination area 12 of the patient's body (i.e., the area of the patient's body that is intended to be examined and is therefore intended to be exposed to radiation 122) in order to expose the examination area 12 to radiation 122 and thereby allow the examination area 12 to be examined. Most of the direct radiation beam 121 enters into the patient's body in order to expose the examination area 12 to radiation 122 and allow the examination area 12 to be examined and subsequently exits the patient's body. The examination area 12 of the patient 10 receives some radiation 122 due to the direct radiation beam 121. The entrance radiation dose 124 is the amount of radiation 122 (both from the direct radiation beam 121 and any scatter radiation 123) that enters into the patient's body, and the exit radiation dose 126 is the amount of radiation 122 that exits from the patient's body.
However, the emitted radiation 122 comprises both the direct radiation beam 121 and scatter radiation 123. In particular, some radiation 122 from the direct radiation beam 121 deflects, which causes the radiation 122 to scatter and form “scatter radiation 123.” Scatter radiation 123 refers to any radiation 122 that is outside of the direct radiation beam 121. A portion of the radiation 122 may scatter before and/or after the radiation 122 enters into and exits from the patient's body. Some of the scatter radiation 123 enters into areas of the patient's body that are not under examination, such as the patient's head and neck (as shown in FIG. 17). Accordingly, these areas of the patient's body not under examination are also exposed to and receive radiation 122 due to the scatter radiation 123, which needlessly increases the patient's overall exposure to radiation 122 (i.e., the entrance radiation dose 124) and also increases the amount of radiation 122 exiting the patient 10 (i.e., the exit radiation dose 126), which may enter into and affect the practitioners.
The practitioners are also exposed to the radiation 122, including both the scatter radiation 123 that has not entered the patient's body and the scatter radiation 123 that has entered and exited the patient's body (i.e., the exit radiation dose 126). The scatter radiation 123 from areas of the patient's body that are not under examination, in particular the patient's head and neck, needlessly increases the amount of radiation 122 that the practitioners are exposed to.
In order to reduce the amount of radiation 122 that the practitioners are exposed to (specifically due to the radiation 122 exiting the patient), lead skirts that are attached to the side of the table 110, mobile shields, suspended plexiglass shields, and sterile pads placed on top of or above the patient 10 may be used. However, most of these devices are only designed to shield the practitioners from the radiation 122 exiting the patient 10. These devices do not protect the patient 10, in particular the patient's head and neck, from excessive radiation 122 (e.g., scatter radiation 123) that enters into these areas of the patient's body not under examination (in particular the patient's head and neck) and instead allow the patient to be needlessly exposed to the scatter radiation 123. Additionally, conventional shielding may not easily be moved to allow visualization of certain anatomical structures when needed.
Therefore, certain procedures, such as cardiac catheterization, expose areas of the patient's body that do not need to be visualized (such as the patient's head and neck, which includes their thyroid) to radiation 122, which needlessly increases both the patient's and the practitioner's overall exposure to radiation 122.
In order to support and stabilize the patient's head (and neck) during radiologic procedures, a conventional non-shielding head support 220 (as shown in FIGS. 18A-21C) may be placed on the table 110 and underneath the patient's head. These non-shielding supports 220 provide a relatively comfortable surface for the patient 10 to rest their head on and prevent the patient's head from moving during the radiologic procedure. The non-shielding supports 220 do not provide any shielding from radiation 122 to the patient 10 or reduce any radiation exposure in order to prevent interference with the radiologic procedure.
The non-shielding supports 220 may have a variety of different configurations as shown in FIGS. 18A-21C. For example, as shown in FIGS. 18A-18B, the non-shielding support 220 may be a gel pad that is shaped like a horseshoe. The non-shielding support 220 of FIGS. 18A-18B is specifically made out of a dry, viscoelastic polymer that is x-ray translucent, radiolucent, and non-conductive. As shown, the non-shielding support 220 of FIGS. 18A-18B includes a keyhole cutout in the middle, which provides a clear air passageway for the patient and aids the anesthesiologist while the patient's body and head are in a variety of different positions. For example, the patient 10 may be laying in a prone, lateral, or side-facing position, and the patient's head may be straight or turned to the side while using the non-shielding support 220, depending on the procedure. The non-shielding support 220 can be sized in order to be suitable for adults or pediatric/neonatal patients. As shown in FIG. 19, the non-shielding support 220 may be a contoured, foam pad or pillow. As shown in FIG. 20, the non-shielding support 220 may be a plastic brace. As shown in FIGS. 21A-21C, the non-shielding support 220 may be a contoured, carbon fiber support.